Bridge plug



June 5, 1951 A. A. BAKER 2,555,627

- BRIDGE PLUG Filed Dec. 22, 1945 Em difiark,

INVENTOR.

ATTORNEY Patented June 5, 1951 BRIDGE PLUG Aaron A. Baker, Coalinga, Galif., assignor to Baker Oil Tools, Inc., Vernon, Calif., a corporation of California Application December 22, 1945, Serial No. 636,849

23 Claims. 3

This invention relates to well devices, and more particularly to well packers employed in the performance of bridging, cementing, acidizing, testing, and similar functions in well bores.

It is sometimes essential or desirable to permit fluid flow through the central passage of a well packer, or like device, and then close this passage against downward flow of the fluent substances. Closing of the passage has heretofore been accomplished by allowing gravitation of a bridging ball, or other element, through the fluid in the tubular string to which the packer is secured, and into engagement with a companion seat in the packer. While this is an effective manner of closing the passage, it entails the consumption of valuable time, especially in deep wells, and, in some instances, bouncing and bumping of the ball along the tubing wall during its downward travel may nick or mar its surface to the point where it will fail to make a fluid tight seal with its companion packer seat.

It is, accordingly, an object of the present invention to obtain prompt seating of the bridging ball in the packer when desired through obviating the need for the ball to travel through the length of the tubing string.

Another object of the invention is to protect the bridging ball or other bridging element of a well packer apparatus against damage during running of the apparatus in the well bore to the desired setting point.

Still a further object of the invention is to protect the bridging element of a well packer apparatus against hydraulic cutting while fluid is being pumped through the apparatus and past the element.

This invention has other objects that will become apparent from a consideration of the embodiment shown in the drawings accompanying and forming part of the present specification.

form will now be described in detail to illustrate the general principles of the invention, but it is to be understood that such detailed description is not to be taken in a limited sense,

since the scope of the invention is best defined by the claims appended hereto.

Referring to the drawings:

Figure l is a longitudinal section through the device of the present invention, with the parts in the positions they assume when the device is being run in the well casing;

Figure 2 is a View similar to Figure 1 showing the device anchored in packed ofi condition in a well casing, and with the running-in string 2 partially unthreaded from the well packer apparatus, and

Figure 3 is a cross-section taken along line 3-3 in Figure 1.

The well packer A and bridging device B illustrated in the drawings are usually lowered through a string of casing C on the lower, end of a suitable tubular string D, such as tubing or drill pipe, to the desired point at which the packer is to be anchored to the casing in packed off condition. The well packer may be of any suitable construction, the one shown being of the type specifically described in United States Letters Patent No. 2,121,051.

Essentially the packer A consists of a tubular body IE3, to which the lower end of the bridging device B is secured. The body has an inflatable packing sleeve H surrounding it, whose upper and lower ends are suitably secured, respectively, to upper and lower conical expanders I2, I3, attached to the body originally by one or more shear screws l4, I5. The outer surface of the upper expander 82 tapers upwardly and inwardly and is engaged by correspondingly tapered upper segmental slips I S secured to it originally in retracted positionby shear screws l'l. Similarly, the outer surface of the lower expander I3 is tapered inwardly in a downward direction and engages correspondingly tapered lower segmental slips l3 secured to it originally in retracted position by shear screws Id. The upper end of the body carries an abutment ring 20 engageable by the upper end of the upper segmental slips i6, and the lower end of the body is provided with a lower abutment 2| for engagement with the lower end of the lower segmental slips [8.

A valve housing and guide 22 is secured to the lower end of the body It, and has a back-pressure ball valve 23, preferably buoyant in cement slurry, originally prevented from engaging its companion valve seat 2!! on the body by a retainer arm 25, which holds the ball against the housing to one side of the central passage 26 through the body. The arm 25 extends upwardly from a trip ball seat 21 secured in the lower end of the valve housing by a suitable shear screw 28.

As aforementioned, the bridging ball retaining and releasing device B is suitably secured to the upper end of the well packer. Specifically, this device consists of a bridging ball housing 29 threaded into the upper end of the body Iii and provided with an enlarged medial chamber 30 in which a bridging ball 31, or corresponding valve element, may be confined. The bridging ball, when released, may drop downwardly a short distance under gravitational influence into engagement with'a valve seat 32 provided in the housing below the chamber 30. V 7

Originally, the bridging ball 3| is held against the inner wall of the chamber 36 to one side of the central passage through the apparatus by a retainer sub 33 threaded into the upper end of the housing 29, preferably through the use of a left-hand thread connection 34. When the retainer sub is in its lowermost position, its depending nose 35 engages the bridging ball 3i and retains it to one side of the axis of the apparatus within the chamber, preventing it from dropping downwardly onto the bridging ball valve seat'32. However, rotation of the tubing string D, as to the right, causes unthreading of the retainer sub 33 from the housing, and elevates its nose 35 'from confining engagement with the bridging ball 3!, allowing the latter to drop onto the bridging ball valve seat; thus closing the central passage of the apparatus against downward flow of fluent substances.

The apparatus is made up as disclosed in Figure 1, with the retainer sub 33 threaded downwardly into the bridging ball housing 29 to its fullest extent to confine the bridging ball 3|, and with the housing itself threaded into the upper end of the body I!) of the well packer. As assurance against unscrewing of the housing 29 from the packer, they may be secured together by a set screw 36. The sub 33is secured to the lower end of the tubular string D, by means of which the apparatus is lowered through the well casing C to the desired packer anchoring point. When this position is reached, a trip ball 37 is allowed to gravitate or is pumped down through the tubing string D through the central passage in the retainer sub 33, past the confined bridging ball valve member 3|, through the body central passage 26, around the back-pressure ball 23 and retainer arm 25, and into engagement with the trip ball seat 21 at the lower end of the apparatus.

Engagement of the trip ball with its seat closes the apparatus against further downward flow of fluid, and enables pressure to be built up to a suificient degree to initiate setting of the packer. Specifically, the fluid under pressure may pass outwardly of the body In, through its lateral ports 38, opening into the interior of the packing sleeve ll, elongating the latter and exerting an upward force against the upper expander i 2 to shear the expander and slip screws l4, ll, moving the expander l2 upwardly along the body H1 and the upper slips Iii radially along the abutment 20 into anchoring engagement with the wall of the casing. Since the upper slips I6 thereby prevent further upward movement of the upper expander l2, the taking of an upward strain on the tubing string D and attached bridging device B and packer body l first compresses the packing sleeve l'l into fluid tight sealing engagement with the packer body it! and casing wall, and then shears the lower expander and slip screws I5, 10, causing the lower abutment 2| to shift the lower slips i8 upwardly along the lower expander 13 and radially outward into anchoring engagement with the wall of the casing. Thereafter, an increase in the fluid pressure to a predetermined degree shears the trip ball seat screw 28, and blows this seat, together with the backpressure ball retaining arm 25, downwardly out of the packer apparatus, freeing the back-pres- 4 sure ball valve 23 for engagement with its companion seat 24. The packer is held in its set position by engagement of a ratchet ring 39 in the upper expander l2 with annular ratchet teeth 49 on the body, which precludes downward movement of the latter with respect to the expander, slips and packing.

Further details of the construction and operation of the well packer of the type illustrated may be found in the patent above referred to.

In one use or the apparatus, cement slurry, or other fluid, may be pumped through the tubing string D and apparatus for discharge from the lower end of the packer A. The bleeding oil of pressure within the tubing string allows the backpressure ball 23 to move upwardly and engage its companion seat 26, preventing return or upward flow of fluid through the packer apparatus.

When it is desired to prevent downward passage of fluent materials through the packer apparatus, the tubular string D is rotated to the right to unthread the retainer sub 23 in an upward direction from the housing 29, elevating the retainer nose 35 from engagement with the bridging ball 3! and allowing the latter to gravitate into engagement with its companion seat 32 in the lower portion of the bridging ball housing. The bridging ball member 38 thus prevents downward passage of fluid through the well packer apparatus, and since the back-pressure valve member 23 prevents upward passage of fluid through the apparatus, a bridging packer is provided which prevents flow of fluid through the apparatus in both directions.

Continued rotation of the tubular string D to the right a sufficient number of turns eventually completely unscrews the retainer sub 33 from the housing and allows removal or" the tubing string and sub from the well bore. The packer A and housing 29 are preferably made of readily drillable materials to facilitate their removal from the casing by a drill bit, if and when desired. By virtue of the apparatus just described, the bridging ball is at or adjacent its seating locating in the well bore. An insignificant amount of time is consumed in rotating the tubular string the partial revolution or several revolutions required to free the bridging ball and allow its engagement with its seat 32. It is unnecessary to await the substantial period of time for a bridging ball to gravitate through. the fluid in the entire tubular string D into engagement with a companion valve seat in the apparatus.

It is also to benoted that the bridging ball or valve element 39 is protected against damage while the apparatus is being lowered in the well bore. The housing 29 precludes any foreign materials or substances in the well bore from engaging and injuring the valve member. Moreover, the valve member 3! is protected against internal damage as a result of hydraulic action companion seat 32 and the provision of a leakproof seal.

Having thus described my invention, what I claim and desire to secure byv Letters Patent is: 1. Well apparatus. including tubular means providin a fluid passage, valve means within said tubularmeans movable downwardly into a position closing said passage, restraining means separate from said valve means and adapted to be connected to a running-in string for lowering said apparatus in a well bore, means providing an axial connection between said restraining means and tubular means in order that rotation of said restraining means will shift said restraining means longitudinally with respect to said tubular means, said restraining means engaging said valve means to, prevent its downward movement into passage closing position and said restraining means being rotatable by said run hing-in string with respect to said tubular means to disengage said restraining means from said valve means and release said valve means for downward movement to passage closing position.

2. Well apparatus, including tubular means providing a fluid passage, valve means within said tubular means movable downwardly into a position closing said passage, tubular restraining means threadedly attached to said tubular means and adapted to be connected to a tubular string for lowering said apparatus in a well bore, said tubular restraining means engaging said valve means when in one position with respect to said tubular means to prevent said valve means from moving downwardly and closing said passage, and said tubular restraining means being rotat able by said tubular string to thread said restraining means with respect to said tubular means to a position releasing said valve means for downward movement to passage closing position.

3. Well apparatus, including tubular means providing a fluid passage and having a valve seat therein, a valve element within said tubular means adapted to engage said seat and close said passage, tubular restraining means threadedly attached to, said tubular means and adapted to be connected to a tubular string for lowering said apparatus in a 'well bore, said tubular restraining means engaging said valve element when in one position with respect to said tubular means to hold said valve means to one side of said, passage and prevent, its engagement with said valve seat, and saidtubular restraining means being rotatable by said tubular string to thread said restraining means with respect to said tubular means to a position releasing said valve element from movement intoengagement with said seat.

l. Well apparatus, including tubular means providing a fluid passage and having a valve seat therein, a valve element Within saidtubular means adapted to move downwardly into engagement with said seat to close said passage, restraining means separate from said valve element and adapted to be connected to a running-in string for lowering said apparatus in a well bore, means providin an axial connection between said restraining means and tubular means in order that rotation of said restraining means will shift, said restraining means longitudinally with respect to said tubular means, said restraining means engaging said valve element to hold it elevated from said seat and to prevent its downward movement onto said seat, and said restraining means being rotatable by said runningsin string with respect to said tubular means to disengage said restraining means from said valve element and release said valve element for downward movement into engagement with said seat.

5 Well. apparatus, including tubular means providing a fluid passage and having a valve seat therein, a ball within said tubular means adapted to move downwardly'into engagement with said seat and close said passage, tubular restraining means threadedly attached to said tubular means and adapted to be connected to a tubular string for lowering said apparatus in a well bore, said tubular restraining means engaging said ball whenin one position with respect to said. tubular means to hold said ball to one side of said passage and prevent its dropping onto said valve seat, and said; tubular restraining means being rotatable by said" tubular string to thread said restraining means with respect to said tubular means-to a position releasing said ballfor downward movement into engagement with said seat.

6. Well apparatus, including tubular means providing a fluid passage and having a valve seat therein, a ball Within said tubular means adapted to' move downwardly into engagement with said seat and close said passage, tubular restraining means threaded within, said tubular means and adapted to be connected to a tubular string for lowering said apparatus in a well bore, said tubular restraining means engaging said ball when threaded downwardly within said tubular means to hold said ballto one side of said passage and prevent its dropping onto said valve seat, and said tubular restraining means being rotatable by said tubular string to thread said restraining means upwardly with respect to said tubular means to a position releasing said ball for downward, movement into engagement with said seat.

7. Well apparatus, including a tubular housing having a chamber therein and a valve seat below said chamber, a ball within said chamber adapted to move downwardly into engagement with said seat, a tubular member attached to said housing and engaging said ball to hold it within said chamber, and means for elevating said member with respect to said housing to disengage said member, from said ball and allow the latter to move from said chamber downwardly into engagement with said seat.

8. Well apparatus, including a tubular housing having a, chamber therein and a valve seat below said chamber, a, valve element within said chamber adapted to move downwardly into engagement with said seat, a tubular member attached to said housing and engaging said element to confine it within said. chamber substantially out of the path of fluid discharge from said tubular member, and, means for elevating said member with respect to said housing to disengage said member from, said element and allow the latter to move from said chamber downwardly into engagement with saidseat.

9. Well apparatus, including a tubular housing having a chamber therein and a fluid passage below said chamber, a valve element within said chamber adapted to move downwardly into said passage, a tubular member attached to said housing and engaging said element to confine it within said chamber substantially out of the path of fluid discharge from said tubular member, and means for elevating said member with respect to said housing to disengage said member from said element and allow the latter to move from said chamber downwardly. into said passage.

19. Well. apparatus, including a tubular housing having a chamber therein and a fluid passage below said chamber, a valve element within said chamber adapted to move downwardly into said passage, a tubular member extending within and threadedly attached to said housing and engaging said element to confine it within said chamber, and means for unthreading said tubular member in an upward direction from said housing to disengage said member from said element andallow the latter to move from said chamber downwardly into said passage.

11. Well apparatus, including a well packer having a passage therethrough, tubular means attached to the upper end of said well packer, a valve element within said tubular means movable downwardly into a position closing said passage, a tubular member attached to said tubular means and engaging said element to prevent it from closing said passage, and means for moving said tubular member with respect to said tubular means to disengage said member from said element and allow the latter to move downwardly and close said passage.

12. Well apparatus, including a well packer having a passage therethrough, tubular means attached to the upper end of said well packer, a valve element within said tubular means movable downwardly into a position closing said passage, a tubular member threadedly attached to the upper portion of said tubular means and engaging said element to prevent it from closing said passage, and means for rotating said tubular member with respect to said tubular means to disengage said member from said element and allow the latter to move downwardly and close said passage.

13. Well apparatus, including a well packer having a passage therethrough, a tubular housing attached to the upper end of said well packer and provided with a chamber therein communicating with said passage and a valve seat below said chamber, a valve element within said chain ber adapted to move downwardly into engagement with said seat to close said passage, a tubular member extending within and threadedly attached to said housing and engaging said element to confine it within said chamber, and means for unthreading said tubular member in an upward direction from said housing to disengage said member from said element and allow the latter to move from said chamber downwardly into engagement with said seat.

14. Well apparatus, including a well packer having a passage therethrough, a tubular housing attached to the upper end of said well packer and provided with a chamber therein communicating with said passage and a valve seat below said chamber, a ball within said chamber adapted to gravitate into engagement with said seat to close said passage, a tubular member extending within and threadedly attached to said housing and engaging said ball to confine it within said chamber, said member being adapted for unthreading from said housing in an up ward direction to disengage said member from said ball and allow the latter to gravitate into engagement with said seat.

15. In combination, well packer apparatus having a fluid passage, valve means within said apparatus movable downwardly into position to close said passage, restraining means separate from said valve means and adapted to be connected to a running-in string for lowering said apparatus in a well bore, means providing an axial connection between said restraining means and apparatus in order that rotation of said restraining means will shift said restraining means longitudinally with respect to said apparatus, said restraining means engaging saidvalve means to prevent its downward movement into passage closing position, and said restraining means being rotatable by said running-in string with respect to said apparatus to disengage said restraining means from said valve means and release said valve means for downward movement to passage closing position.

16. In combination, well packer apparatus having a fluid passage, valve means within said apparatus movable downwardly into position to close said passage, restraining means separate from said valve means and adapted to be connected to a running-in string for lowering said apparatus in a well bore, means providing an axial connection between said restraining means and apparatus in order that rotation of said restraining means will shift said restraining means longitudinally with respect to said apparatus, said restraining means and apparatus cooperatively engaging said valve means to prevent its downward movement to passage closing position, and said restraining means being movable by said running-in string with respect to said apparatus to disengage said restraining means from said valve means and release said valve means for downward movement to passage closing position.

1'7. Well apparatus, including tubular means providing a fluid passage, valve means within said tubular means movable downwardly into position for closing said passage, tubular restraining means threadedly attached to said tubular means and adapted to be connected to a tubular string for lowering said apparatus in a well bore, said tubular restraining means and tubular means cooperatively engaging said valve means when said restraining means is in one position withrespect to said tubular means to prevent said valve means from moving downwardly and closing said passage, and said tubular restraining means being rotatable by said tubular string to thread said restraining means with respect to said tubular means to a position releasing said valve means for downward movement to passage closing position.

18. In combination, well packer apparatus having a fluid passage and a valve seat therein, a valve element within said apparatus adapted to engage said seat and close said passage, tubular restraining means threadedly attached to said apparatus and adapted to be connected to a tubular string for lowering said apparatus in a well bore, said tubular restraining means engaging said valve element when in one position with respect to said apparatus to hold said valve means to one side of the axis of said passage and prevent its engagement with said valve seat, and said tubular restraining means being rotatable by said tubular string to thread said restraining means with respect to said apparatus to a position releasing said valve element for movement into engagement with said seat.

.19. In combination, well packer apparatus having a fluid passage and a valve seat in said passage, a valve element within said apparatus adapted to move downwardly into engagement with said seat to closesaid passage, restrainsaid seat, and said restraining means being movable by said running-in string with respect to said apparatus to be disengaged from and release said valve element and allow its downward movement into engagement with said seat. 20. In combination, well packer apparatus having a fluid passage and a valve seat therein, a ball within said apparatus adapted to move downwardly into engagement with said seat and close said passage, tubular restraining means threadedly attached to said apparatus and adapted to be connected to a tubular string for lowering said apparatus in a well bore, said tubular restraining means and apparatus cooperatively engaging said ball to prevent its dropping on to said valve seat, and said tubular restraining means being rotatable by said tubular string to thread said restraining means with respect to said apparatus to a position releasing said ball for downward movement into engagement with said seat.

21. Well apparatus, including a tubular housing having an imperforate chamber therein and a valve seat below said chamber, a ball within said chamber adapted to move downwardly into engagement with said seat, tubular means attached to said housing and engaging said ball to hold it Within said chamber, and means for elevating said tubular means with respect to said housing to disengage said tubular means from said ball and allow the latter to move from said chamber downwardly into engagement with said seat.

22. Well apparatus, including a well packer having a passage therethrough, a tubular housing attached to the upper end of said well packer and provided with a chamber therein communicating with said passage and also with a valve seat below said chamber, a valve element within said chamber adapted to move downwardly into engagement with said seat to close said passage, a tubular member extending within and threadedly attached to said housing and engaging said element to confine it within said chamber to one side of said tubular member, and means for threading said tubular member in an upward direction from said housing to disengage said member from said element and allow the latter to move from said chamber downwardly into engagement with said seat.

23. Well apparatus, including tubular means providing a fluid passage, valve means within said tubular means movable downwardly into a position closing said passage, restraining means separate from said valve means and adapted to be connected to a running-in string for lowering said apparatus in a well bore, means providing an axial connection between said restraining means and tubular means in order that rotation of said restraining means will move said restraining means upwardly with respect to said tubular means, said restraining means engaging said valve means when in a downward position with respect to said tubular means to prevent downward movement of said valve means into passage closing position, and said restraining means being rotatable by said running-in string with respect to said tubular means to elevate said restraining means with respect to said tubular means and valve means and thereby disengage said restraining means from said valve means and release said valve means for downward movement to passage closing position.

AARON A. BAKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 984,084 Farrah Feb. 14, 1911 1,244,833 Burich Oct. 30, 1917 2,187,487 Burt Jan. 16, 1940 2,222,233 Mize Nov. 19, 1940 2,270,648 Church Jan. 20, 1942 2,320,670 Scaramucci June 1, 1943 2,368,409 Burt Jan. 30, 1945 2,378,469 Denton June 19, 1945 

